Field
Embodiments of the present disclosure generally relate to an inject insert for use in semiconductor processing equipment.
Description of the Related Art
Some processes for fabricating semiconductor devices, for example rapid thermal processing, epitaxial deposition, chemical vapor deposition, physical vapor deposition, electron-beam curing, are performed at elevated temperatures. Usually substrates being processed are heated to a desired temperature in a processing chamber by one or more heat sources. The one or more heat source is typically mounted outside the chamber body so that the energy generated by the heat source radiates upon the substrate positioned within the chamber body.
Processing gases are usually supplied to the chamber from a gas inlet, and are kept flowing in the chamber by a pumping system connected to chamber. Gas distribution in a conventional chamber is not uniform across the chamber. For example, gas distribution near the gas inlet is different from gas distribution near the pumping port, and gas distribution near the edge region is different from gas distribution near the center region.
Further, some chambers may include multiple flow zones having different process gases or gas flow rates which feed into a single channel defined within the gas inlet. As a result of the “crosstalk” between the multiple flow zones feeding into a single gas inlet, attempts to tune the gas flow distribution within the processing chamber by varying the type of gas or gas flow rate in the different flow zones have unpredictable tuning results.
Additionally, in operation, localized zones of cyclically flowing gas, known as “recirculation cells,” often form within the channels of inject inserts used in conventional gas manifolds. Recirculation cells result in degraded uniformity of the gas flow distribution within the processing chamber, which results in strong variations in epitaxially-grown films.
Continuous rotation has been previously employed in an attempt to resolve some of the above non-uniformity issues. In theory, continuous rotation delivers a majority of the substrate to a variety of flow zones such that flow zone non-uniformity is minimized. Although, continuous rotation of the substrate may reduce the non-uniformity of gas distribution, the rotation alone may not be enough as the requirement for uniformity increases. The foregoing problems attributable to conventional gas inlets are amplified when the flow rate of the process gas is increased, which is desirable to increase the throughput of the CVD device.
Therefore, there is a need for a thermal reactor with improved gas flow distribution.